Grading machine



Dec. 20, 1955 DE WITT E. NEIBEL ET AL 2,727,624

GRADING MACHINE Q Filed July 25, 1951 2 Sheets-Sheet 1 I N V EN TOR5. 06M77 Ne/ Ze/ Ber/7a fl fssma/efler' Dec. 20. 1955 DE WlTT E. NEIBEL ET AL2,727,624

GRADING MACHINE Filed July 25, 1951 2 Sheets-Sheet 2 INVENTORS. 539144775. A e/fe/ United States Patent GRADING MACHINE DeWitt E. Neibel andBernard H. Essmneller, Kansas City, Mo.

Application July 23, 1951, Serial No. 238,042

9 Claims. 01. 209-104 This invention relates to apparatus for gradingfungible materials such as grain and the like according to the relativethickness or diameter of the individual particles, and refers moreparticularly to improvements in rotary grading machines of the typedisclosed in U. S. Patent No. 1,898,249, dated February 21, 1933, andissued on application of John W. Hoefling.

While reference may be had to the above patent for a more detaileddescription of the principle upon which machines of this type depend foroperation, basically they may be said to comprise at least two diskswhich taper in thickness from a maximum at their centers to a minimum atthe periphery and which are coaxially mounted in close arrangement on arotatable shaft. By virtue of the tapering thickness of the disks, thedistance between the proximal faces increases from a minimum near theshaft to a maximum at the outer edge and as the unsized material is fedthereinto, the individual particles will come to rest at a point wherethe distance between the disks is substantially equal to the thicknessor diameter of the particular particle. Thus the fine particles willtravel inwardly to a point near the axis of rotation, and the largerparticles will range outwardly therefrom, the distance from the centerdepending in each case on the size of the particle.

In standard machines of this type, the unsized material is fed bygravity from a hopper or other suitable feed means positioned above thedisks, becoming wedged between the disks, and through rotation iscarried to a point substantially opposite the hopper where it isdislodged and collected in the grades desired. The dislodging andcollection is accomplishedthrough the use of stationary fingers whichare positioned between the disks to lie in the path of the oncomingparticles and which terminate at varying distances from the center ofthe disks, those designed to catch the finest particles extendingsubstantially to the shaft and the others having their ends spaced atincreasing distances therefrom whereby each finger is adapted to catchparticles of a designated size. Once dislodged, the particles fall freeof the disks, and are directed into suitable receptacles according tothe desired grade. The operation of the machine is continuous, and sincethe only resistance to be overcome in rotating the disks is the frictionin the shaft bearings, machines of this type offer a considerableadvantage over the previously known vibrating-screen graders or similardevices.

However, while in principle machines of this type represent a markedimprovement over previously known devices, a number of problems arise inconstructing the machines so that their operational efficiency is at theoptimum. In the first place, since the dislodgingfingers are normallyrigidly positioned within the space between the disks, and since toinsure that all particles traveling in the path intercepted by thefingers will be removed the fingers must necessarily fit closely withthe respective faces of the disks, any imperfections either in machiningthe faces of the disks or aligning them with the nected to any suitablerotary drive means, such as an elec-,

"ice

axis of rotation will cause binding between the fingers and the disks.The binding, 'of course, can be eliminated by narrowing the thickness ofthe fingers to appreciably less than the spacing between the disks;however, the opportunity then exists for the particles to wedge betweenthe fingers and the disks which may result either in damage to thematerial being graded or jamming the operation of the machine. I

Broadly speaking, therefore, it is an object of our invention to providea rotary grading machine of the general type describedabove in which thefingers fit closely within the space between the disks and yet which areselfadjusting to compensate for inaccurate alignment of the disks on thedrive shaft or imperfections in the disk faces resulting from impropermachining.

Another object is to provide a machine of this type in which the fingersextending inwardly to a point adjacent the drive shaft are separatedtherefrom by means of a stationary buifer, thus preventing anyengagement between the end of the fingers and the rotating shaft. Inthis connection, it is a further object to provide a buffer which may beinstalled and removed from the machine with little effort.

Still another object is to provide positive means for controlling therate at which material is fed between the disks, thus insuring optimumresults both as to capacity and accuracy of grading.

Other and further objects, together with the inherent features ofnovelty, will appear in the course of the following description.

In the accompanying drawings which form part of the specification andare to be read in conjunction therewith, and in which like referencenumerals are employed to indicate like parts in the various views:

Fig. 1 is a front elevational view of a machine embodying ourinventionjp arts being broken away for purposes of illustration. 5

Fig. 2 is a sectional view taken along line 22 in Fig. 1, in thedirection of the arrows.

Fig. 3 is a fragmentary section taken along line 33 in Fig. 2, in thedirection of the arrows.

Fig. 4 is a detail view of the dislodging fingers as seen in Fig. 1showing the method of attachment to their supporting structure, some ofthe fingers having been removed for clarity of description.

Referring now to the drawings, forming the main body of a gradingmachineembodying our invention is an enclosed casing, preferably constructed ofsheet metal, having a bottom wall 10, side walls 12, a rear of back wall14, and a sectionally canted front wall 16. A troughlike open top hopper18, partially filled with unsized material 20, such as wheat or thelike, spans the top 22 of the casing between the side walls 12, and theforward wall 18a of'the hopper extends downwardly for a short distanceinto the interior of the casing where it is arced upwardly to form asemicircular lip or trough 1812. P0- sitioned above and fitting closelywith the curvature of lip 18b is a horizontally disposed cylindricalmember 24 having a plurality of longitudinal grooves or flutes 26 aroundits periphery to form a star-wheel like gate for controlling the rate offeed of unsized material into the casing. Member 24 is mounted on acoaxial shaft 28 rotatably journaled on opposite sides 12 of the casingin suitable bearings 30, and, as will be discussed more fullyhereinafter, is positively connected to the main drive of the machine.

Positioned substantially centrally in the casing and extending from sideto side thereof parallel with hopper 18 is a second shaft 32 which isrotatably journaled in the side walls 12 of the casing in bearings 34.One end of the shaft, 32 is provided with a drive coupling 36 contricmotor (not shown) and connecting shaft 32 with the star-wheel shaft 28is a drive chain 38 which passes around toothed sprockets 40 and 42secured respectively to shafts 23 and 32.

. Encircling shaft 32 within the walls of the casing and connected torotate therewith by means to be presently described are a plurality ofradially tapered disks 44 which are closely arranged to provide betweentheir inwardly converging faces a plurality of annular V-shaped grooves46. Each disk decreases uniformly in thickness radially outward from itsflattened center section 44a, and separating each pair of disks is arelatively thin shim or washer 48 having a diameter substantially equalto the flattened center section 44a of the disks. The periphery 48a ofeach shim forms the base of each groove 46, and as may be bestappreciated from Fi g. 2, the width of the groove increases uniformlyoutwardly therefrom by virtue of the tapered thickness of each disk.

Referring now more particularly to Fig. 3, forming the means ofattachment of disks 44 to shaft 32 is a hublike member 50 rigidlysecured to the shaft at one end of the disk assembly and into which arethreaded a pair of elongate bolts 52 disposed on opposite sides of andparallel to the shaft. Each of the disks 44 and shims 48 is providedwith a pair of diametrically opposed holes corresponding in locationwith bolts 52, and located at the opposite end of the disk assembly fromhub member 50 is a disk-like face plate 54 which is also loosely mountedover bolts 52 and shaft 32, and which may be forced axially toward thehub 50 by means of a pair of nuts 56 mounted on ends 52b of the bolts,thus maintaining disks 44 in tight axial contact along the shaft. Ineffect, the disk arrangement set out above provides a compact rotorhaving a plurality of side by side annular V-shaped grooves, and itshould be apparent that in the alternative, the same may be accomplishedthrough suitable machining of one solid piece of material. Through theuse of disks and the foregoing method of attachment, a grading machineis provided in which the individual disks may be readily detached fromthe shaft for inspection or replacement with minimum effort.

Returning now to Fig. 2, providing means for feeding unsized materialfrom hopper 18 into the grooves 46 between disks 44 is a plurality ofcoplanar finger-like members or teeth 58, one for each groove, which aredisposed below the upcurved lip 18b of the hopper and which extenddownwardly and inwardly between the disks in a comb-like arrangement atan angle of substantially 45. The teeth 58 are mounted in a manner to beprescritly described on a support bar or plate 60 extending transverselythrough the casing and secured at its ends to side walls 12, andextending downwardly from the top 23 of the casing is a stationarydeflection shield 62 for preventing particles being discharged from thehopper from passing downwardly around the support 60 into the bottom ofthe casing. In this connection, it will be noted from Fig. 1 that sincethe opposite ends of the disk assembly are spaced inwardly from the sidewalls 12 of the casing, the space between the end disks and the sidewall is blocked off by means of filler plates 64 rigidly secured to thecasing Wall and cut out around the shaft 32 and hub 50. The inner faceof each filler plate 64 is faced as indicated at 66 with a soft materialsuch as felt to prevent wear during rotation.

Positioned on the opposite side of the disk assembly from feed teeth 58,and extending upwardly and inwardly into grooves 46 between disks 44 area plurality of dislodging teeth 68 which are arranged in three parallelbanks according to length. Similarly to feed teeth 58, the teeth 68 ofeach bank are mounted in a manner to be presently described on astationary support bar 70 secured at its ends to the side walls 12 ofthe casing, and are tapered in thickness to correspond with the taperedwidth of grooves 46 (see Fig. 1). The teeth 68 of each bank are of equallength, and as shown in the drawings, those in the lower bank extendinwardly substantially to the bottoms of the grooves 46 while those insucceeding banks terminate at increasing distances therefrom. Thus, theparticles carried between disks 44 are intercepted by the teethaccording to their radial spacing from the axis of rotation, and aredirected into separate discharge passageways 72 below the support bars60 formed by partitions 74 extending transversely through the casing.

Forming a novel feature of our invention is the means of attachment ofthe feed teeth 58 and dislodging teeth 68 to their respective supportbars 60 and 70. As is particularly evident from Fi g. 2, provided in thelower surface of each tooth near its outer end is a small rectangularnotch or slot 53a, 68a, which is slightly wider than and loosely engagedby a shoulder-like key 60a, 7%, extending lengthwise of and secured tothe upper surface of the support bars as, (see Fig. 4). To hold thefingers down on the support bar, a cover plate 76 having a generallyL-shaped cross-section is positioned above the teeth and secured to thesupport bar by bolts 78 and nuts 80. In order to prevent binding betweenthe cover plate 76 and the teeth 58, 68, a spacing bar 82 having athickness slightly greater than the vertical thickness of the teeth isinterposed between the cover plate and the support bar outwardly of theends 58b, 68b, of the teeth. It should be evident from the foregoingthat while the teeth are prevented from longitudinal movement by key60a, 70a, they are still free to shift axially of shaft 32 and to pivotslightly about the key 60a,70a in the channel formed by cover plate 76and the support 70. Thus, should the disks 44 be out of alignment Withshaft 32, or should there be any imperfections in machining the faces ofthe disks, the lateral play aflorded by the key 60a, 70a, and slots 58a,68a, will permit the teeth to adjust themselves accordingly. The edges76a of the cover plate 76 extend inwardly to lie closely adjacent theperiphery of disks 44 to prevent particles from falling between theteeth 58, 68, as they travel to or from the grooves 46, and are slightlytapered in thickness for smooth passage of the particles thereover.

Forming another novel feature of our invention is the provision of meansfor providing a tight seal between the ends of the feed teeth 58 andlower bank of the dislodging teeth 68 and the periphery 48a of therotating shims 48 carried between each pair of disks 44. As may be bestappreciated from Figs. 2 and 3, hooked over the top of each shim 48 isthe curved end 84a of a relatively thin J-shaped buffer plate 84 whichis provided with an elongated stem extending downwardly and rearwardlyaway from the axis of rotation. The stems of the buffer plates 84 areattached externally of grooves 46 to a shaft-like support 86 parallelingshaft 32 and affixed at its ends to the side walls 12 of the casing.Concentric with the shaft 32, the inner edges of the buffer plates 84rest in sliding contact with the shim peripheries 48a, and the ends ofthe stationary teeth 58 and 68 bear against the outer edge of the bufferplates; thus any tendency of the fingers to dig into the shims whichmight result from attempting to maintain them in close contact therewithis effectively eliminated.

The operation of our invention should be fairly evident from theforegoing description. As the disk assembly is rotated in the directionshown by the arrow in Fig. 2, shaft 28, driven by chain 38, rotates feedmember 24 in the direction shown by the arrow, and the unsized material20 is fed from hopper 18 into the casing and onto the surface of coverplate 76 covering feed teeth 58. Traveling down the feed teeth 58, theparticles distribute themselves according to size in the tapered grooves46 between the disks 44, and becoming wedged therein, are carriedthrough substantially a half revolution where they are intercepted bythe dislodging teeth 68. Removed from between the disks 44 by teeth 68,the particles intercepted by the respective banks fall over the ends ofthe cover plates 76 into passageways 72 and are collected by anysuitable means. By virtue of the positive connection of feed memher 24with the rotating disk assembly, 'the material is fed between the disksat a rate which insures against clogging of the grooves and failure todistribute properly therein. The relatively close fit between the disksand the sides of the feed teeth 58 and dislodging teeth 68 prohibits thewedging of particles therebetween, and the tight seal at the inner endsof the teeth afforded bybuffer plates 84 prevents fragments or extremelyfine particles from falling into the bottom of the casing. Duringrotation of the disk assembly, the teeth 58 and 68 are free to adjustthemselves laterally (as has hereinbefore been pointed out), thusallowing them to be more accurately fitted into the grooves than if theywere held rigid. Through the self-adjusting mounting of the teeth, theaccurate fitting of the teeth into the grooves, and the positive controlof the rate of feed, a grading machine is provided which assures of theaccurate separation of the particles according to their thickness ordiameter and in which the rate at which materials may be graded ismaintained at the optimum.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the invention.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illus-. trative and not in a limiting sense.

Having thus described our invention, we claim:

1. In a grading machine, a generally cylindrical rotor mounted to turnabout a horizontal axis, said rotor containing a plurality of annulargrooves disposed side by side along the length of the rotor, theopposite side walls of each groove converging toward the center of therotor whereby the groove is substantially V-shaped in radial crosssection, a support fixedly positioned adjacent the periphery of therotor, a plurality of coplanar laterally spaced teeth projecting fromsaid support into the respective ones of said grooves, said supportcomprising a channel having parallel side walls, said teeth having shankportions loosely confined between said side walls for sliding movementrelative thereto, whereby each tooth has a side surface confronting theinterior surface of one of said side walls, a slot in one of saidsurfaces paralleling the axis of the rotor, a key on the other of saidsurfaces also paralleling the axis of the rotor and projecting into saidslot to substantially prevent sliding movement of the tooth in thedirection of its longitudinal axis while permitting movement of thetooth parallel to the axis of the rotor, and each tooth tapering towardits tip to conform to the side walls of the groove into which itextends.

2. A machine as in claim 1 wherein said slot in each tooth is slightlywider than said key whereby said tooth enjoys limited free pivotalmovement relative to said support.

3. In a grading machine, a generally cylindrical rotor mounted to turnabout a horizontal axis, said rotor containing a plurality of annulargrooves disposed side by side along the length of the rotor, theopposite side walls of each groove converging toward the center of therotor whereby the groove is substantially V-shaped in radial crosssection, a buffer in each groove at least partly encircling the axis ofthe rotor, each buffer having a bearing surface curved circumferentiallyof the rotor to conform with and seat against the base of the groove,means for anchoring said buffers against rotation with the rotor, asupport fixedly positioned adjacent the periphery of the rotor, aplurality of coplanar laterally spaced teeth projecting from saidsupport into the respective ones of said grooves and having their tipsabutting against said butfers .in the respective grooves, each toothtapering toward its tip to conform to the side walls of the groove intowhich it extends, each tooth mounted on said support for limitedsidewise movement independently of the other teeth, and coactingelements on the teeth and support substantially preventing the teethfrom moving longitudinally relative to said support.

4. In a grading machine, a generally cylindrical rotor mountedto turnabout a horizontal axis, said rotor containing a plurality of annulargrooves disposed side by side along the length of the rotor, theopposite side walls of each groove converging toward the center of therotor whereby the groove is substantially V-shaped in radial crosssection, a bufier in each groove at least partly encircling the axis ofsaid rotor, each buffer having a bearing surface curvedcircumferentially of the rotor to conform with and seat against the baseof the groove, means for anchoring said buffers against rotation withthe rotor, and a comb-like member mounted beside the rotor with itsteeth projecting into the respective grooves, the tip of the tooth ineach groove abutting against the buffer in that groove.

5. A machine as in claim 4 wherein each buffer comprises a J-shapedmember having a curved end concentric with the axis of the rotor and anelongated stern projecting outwardly from said end to a point beyond theperiphery of the rotor, and said anchoring means comprising a stationarysupport beside said rotor having the projecting portion of said stemsconnected thereto.

6. In a grading machine, a generally cylindrical rotor mounted to turnabout a horizontal axis, said rotor containing a plurality of annulargrooves disposed side by side along the length of the rotor, theopposite side walls of each groove converging toward the center of therotor whereby the groove is substantially V-shaped in radial crosssection, a buffer in each groove at least partly encircling the axis ofthe rotor, the buffer in each groove having a bearing surface curvedcircumferentially of the rotor to conform with and seat against the baseof the groove, means for turning the rotor, means anchoring said buffersagainst rotation with the rotor, a comb-like member mounted beside saidrotor with its teeth projecting into the respective grooves, said teethbeing inclined downwardly toward their tips and the tips of the teethabutting said buffers in the respective grooves, means for feedingunsized material along said teeth into said grooves, and a secondcomb-like member mounted beside said rotor in a position substantiallyopposite the position of said first member, said second member havingstripping teeth extending into the respective grooves.

7. A machine as in claim 6 wherein the tips of the teeth of said secondcomb-like member abut against said buffers in the respective grooves.

8. In a grading machine, a generally cylindrical rotor mounted to turnabout a horizontal axis, said rotor containing a plurality of annulargrooves disposed side by side along the length of the rotor, theopposite side walls of each groove converging toward the center of therotor whereby the groove is substantially V-shaped in radial crosssection, a buffer in each groove at least partly encircling the axis ofthe rotor, the bufifer in each groove having a bearing surface curvedcircumferentially of the rotor to conform with and seat against the baseof the groove, means for turning the rotor, means anchoring said buffersagainst rotation with the rotor, a comb-like member mounted beside therotor with its teeth projecting into the respective grooves, said teethbeing inclined downwardly toward their tips and the tips of the teethabutting .said buffers in the respective grooves, a hopper above saidrotor adapted to receive unsized material to be graded, said hopperhaving above said member a discharge opening elongated in a directionparallel to the axis of the rotor and substantially coterminoustherewith, a closure for said opening comprising a fluted cylindermounted to turn about an axis parallel to the axis of the rotor, a driveconnection from said rotor turning means to said cylinder whereby saidcylinder is adapted to feed the unsized material from said hopper ontosaid comb-like member at a rate dependent upon the rate of rotation ofthe rotor, said material adapted to flow downwardly along said inclinedteeth into said groove, and a second comb-like member mounted besidesaid rotor in a position substantially opposite the position of saidfirst member, said second member having stripping teeth extending intothe respective grooves.

9. In a grading machine, a generally cylindrical rotor mounted to turnabout a horizontal axis, said rotor containing a plurality of groovesdisposed side by side along the length of the rotor, the opposite sidewalls of each groove converging toward the center of the rotor wherebythe groove is substantially V-shaped in radial cross section, a supportmember substantially parallel with the axis of the rotor and fixedlypositioned adjacent the periphery of the rotor, a plurality of coplanarlaterally spaced teeth extending from said support into the respectiveones of said grooves and having their inner ends spaced from the basesof said grooves, the teeth being tapered to conform to the side Walls ofthe respective grooves into which they extend, a member cooperating withsaid support member and said teeth to prevent movement of said teethtransverse to the plane of the teeth while permitting free sidewisemovement of each tooth in the plane of the teeth independently of theother teeth, and coacting elements on the teeth and supportsubstantially preventing the teeth from moving longitudinally Within thegrooves thereby to preserve the spacing of the inner ends of the teethfrom the bases of the grooves.

References Cited in the file of this patent UNITED STATES PATENTS110,124 Douglas et a1. Dec. 13, 1870 558,900 Dougan Apr. 21, 1896631,093 Richards et a1. Aug. 15, 1899 836,869 Deaver Nov. 27, 19061,541,903 Crites June 16, 1925 1,898,249 Hoefiing Feb. 21, 19331,899,737 Ulrich Feb. 28, 1933 1,941,147 Hans-Joachim Jonlige Dec. 26,1933 2,091,815 Hommel Aug. 31, 1937 FOREIGN PATENTS 442,269 GreatBritain Feb. 5, 1936 600,345 Germany July 20, 1934 615,179 Germany June28, 1935 640,610 Germany Jan. 8, 1937

